3) (2 3/8 : 3/4 + 24 7/9) / (7 1/8 - 157 4/5 : 24)

1. Convert mixed numbers to improper fractions: (19/8 : 3/4 + 223/9) / (57/8 - 789/5 : 24).
2. Perform division and addition in the numerator: (19/8 * 4/3 + 223/9) = (19/6 + 223/9) = (57/18 + 446/18) = 503/18.
3. Perform division and subtraction in the denominator: (57/8 - 789/5 * 1/24) = (57/8 - 263/40) = (285/40 - 263/40) = 22/40 = 11/20.
4. Perform final division: (503/18) / (11/20) = 503/18 * 20/11 = 10060/198 = 5030/99 = 50 80/99.